1. Field of the Invention
The present invention relates to a modular jack, and more particularly to a modular jack having improved magnetic module efficiently eliminating electromagnetic interference to signal transmitted therethrough.
2. Description of Prior Arts
U.S. Pat. No. 5,736,910 issued to Townsend et al on Apr. 7, 1998 discloses a modular jack mounted onto a mother printed circuit board and adapted for receiving a plug. The modular jack includes a housing defining a receptacle, a daughter printed circuit board attached to a rear portion of the housing, a first set of contacts mounted to the housing for engaging with the plug and a second set of contacts assembled to the printed circuit board for connecting to the mother printed circuit board. A plurality of groups of toroidal coil pairs are interposed between the first contacts and the second contacts for eliminating high frequency noise. Each toroidal coil pair has a first toroidal core functioning as a common mode filter, a second toroidal core functioning as a transformer. Each toroidal coil pair has at least a coil wound around the first toroidal core and the second toroidal core for electrically connecting the first core and the second toroidal cores together.
U.S. Pat. No. 5,069,641 issued to Sakamoto et al. disclose a modular jack to be mounted on a circuit board, and the modular jack has a printed board containing a noise suppressing electronic element in a housing. The printed board is fitted with contactors for contacting with plugs and terminals to be used for mounting the modular jack on the circuit board. The contactors and the terminals are electrically connected with the noise suppressing electronic element by wires on the printed board.
In general, it need more space for locating such a large number of the toroidal coil pairs between the first and the second set of contacts, which increase the cost of manufacture.
Hence, it is desirable to provide an improved modular jack to overcome the aforementioned disadvantages.